WO2008031587A2

WO2008031587A2 - Drive energy supply in rail vehicles

Info

Publication number: WO2008031587A2
Application number: PCT/EP2007/007966
Authority: WO
Inventors: Johannes Scholten
Original assignee: Bombardier Transportation Gmbh
Priority date: 2006-09-14
Filing date: 2007-09-07
Publication date: 2008-03-20
Also published as: WO2008031587A3; DE502007005788D1; EP2067227B1; EP2067227A2; DE102006043941A1; ATE489756T1

Abstract

The invention relates to an arrangement for supplying drive energy to a rail vehicle, wherein the arrangement has the following: a first mains power converter (1) with an assigned smoothing capacitor (2), at least a first motor power converter (15) with an assigned smoothing capacitor (17), connecting lines (21a, 21b) between the first mains power converter smoothing capacitor and the first motor power converter smoothing capacitor, a second mains power converter (2) with an assigned smoothing capacitor (4), connecting lines (7a, 28) between the first mains power converter smoothing capacitor (3) and the second mains power converter smoothing capacitor (4), wherein the connecting lines between the two mains power converter smoothing capacitors form a loop together with the mains power converter smoothing capacitors. By virtue of the line connections, the loop has an inductance and forms an LC resonant circuit with the capacitors. The arrangement may also have one or more concentrated reactors which are inserted into the line connections of the loop in order to increase the inductance of the loop selectively. The arrangement has valves in the mains power converters, which valves are switched with a clocking frequency so that a pulse frequency is set at each mains power converter smoothing capacitor. The entire inductance of the loop is selected such that the resonant frequency of the loop is in a range of plus/minus 10% of twice the pulse frequency.

Description

Drive power supply for rail vehicles

The invention relates to an arrangement for the drive power supply of a rail vehicle. The invention further relates to a rail vehicle having such an arrangement. The term rail vehicle is also a rail vehicle association, z. B. understood a train with multiple railcars.

The arrangement is an arrangement with converters and their connections. In this case, network-side converter (rectifier), hereinafter referred to as mains converter, with motor-side converters (inverter), hereinafter referred to as a motor power converter connected.

AC drives for rail vehicles, which are usually operated on an AC overhead line, usually have a mains converter (rectifier), which is commonly connected as a 4-quadrant (hereinafter also referred to as 4QS) to the secondary side of a transformer. The DC side of the power converter is usually connected to a smoothing capacitor whose voltage is kept at a desired value by a power converter control. The line inductance between the smoothing capacitor and the mains converter must be low, since otherwise switching overvoltages will occur at the valves during cyclic operation of the valves of the mains converter. This applies both to IGBT (Insulated Gate Bipolar Transistor) and to GTO (Gate Turn Off) valve sets.

From the smoothing capacitor of the mains converter, the DC side of the connected or the connected inverter is fed. Also for the motor inverter, a smoothing capacitor is provided again, the short lines with the inverter valve sets connected is. Therefore, at least two smoothing capacitors are connected to each other by one plus and one minus line, ie two DC voltage lines at different electrical potential. The plus and minus line, possibly with the components connected thereto or provided therein, such as the smoothing capacitors and at least one smoothing choke (see below) is also referred to here as a DC intermediate circuit, although the lines themselves do not form a closed loop (mesh).

However, such an arrangement of capacitors and the unavoidable line inductances is an oscillatory system (LC resonant circuit). Typical cable lengths of a few meters result in resonance frequencies around 1 kHz. However, the range between 100 Hz and 10 kHz is disadvantageous for the operation, since in this area usually the clock frequencies of the connected mains and motor converter are. Therefore, in the arrangements relating to this invention, the motor power converters are connected to the spatially remote power converters via smoothing chokes with resonant frequencies below 100 Hz.

If the resonant frequency of the LC resonant circuit is below 100 Hz, the oscillation amplitudes can be kept small by control measures or by passive vapor deposition. Above 10 kHz, the vibration amplitudes due to current displacement in the lines or by additional damping are low. In addition, the amplitude of the oscillations above 10 kHz and below 100 Hz is not high, since the suggestions take place substantially in the range of the valve switching frequencies of a few 100 Hz to a few kHz.

Because of the vibration problem is so far forced to set power converter and drive inverter relatively close to each other, for example, side by side or back to back with cable lengths of maximum one to two meters. Therefore, the freedom in the spatial arrangement of the power converter in the rail vehicle are severely limited. Also, an optimum weight distribution of the drive components can often not be achieved. A poor division leads to an unfavorable axle load utilization.

Another problem relates to rail vehicles that were designed for operation on DC power grids and in which the engine inverters are spatially far away from each other provided or installed. When an AC trolley feed is to be supplemented to allow two-system operation, there is often no room for the power converter in the motor inverter area.

If several mains converters are to be provided, for example in order to enable higher power levels or to achieve redundancy, the following possibilities exist: a) Independent, ie galvanically separated, drive systems can be provided. Mains converter and motor converter are arranged in this case spatially close. A smoothing choke between mains converter and motor converter is then not required. b) All converters are arranged very close to each other, so all mains converters and motor converter are united in one place. c) The power converters will be placed close to each other. The motor-mounted converters are connected to the power converters via smoothing reactors. The mains converters should be galvanically connected. d) The power converters are connected to each other via at least one smoothing reactor. The motor power converters are connected to the mains converter via at least one additional smoothing choke. In total, at least 3 smoothing throttles are required. Solution b) is often implemented in locomotive drives. But this is not possible for a multiple unit train with distributed drives. There, the solution is often chosen a), the compulsion, (based on a drive system) motor power converter and power converter set up close to each other, remains, if you do not want to install smoothing reactors between motor power converter and power converter.

Possibility c) has the disadvantage that the power converter must be placed close to each other. However, it is desirable to overcome this limitation without having to accept the disadvantages of a third smoothing reactor.

One way to spatially separate power converters from each other but to connect galvanically is the electrical connection of the two DC voltage intermediate circuits, d. H. the smoothing capacitors with each other, wherein at least one smoothing reactor is provided in the compound. The smoothing choke reduces the resonant frequency of the oscillations to such an extent that control or passive damping can take place, typically below 100 Hz oscillation frequency (see above).

The following problem concerns another aspect of distributed converter systems which can optionally be implemented in addition to the main aspect of the invention: If the grid converter is also to be regenerative, ie braking energy is to be fed back into the grid (this is required nowadays) by applying a 4-quadrant adjuster, it comes with short contact interruptions between pantograph and mains to interrupt the mains current. Even a sudden valve lock in the mains converter due to the response of internal monitoring leads to the interruption of the mains current. The result is too high voltages on the smoothing capacitor of the mains converter. These overvoltages occur because the smoothing reactors between the motor inverter and Mains converter in braking mode, the current flow from the motor converter to the power converter initially maintained, the energy but the network side no longer finds takers. This energy will now charge the power converter smoothing capacitor so that its voltage rises sharply. Thus, impermissibly high voltage values can also be achieved for the semiconductor valves of the mains converter. There were two ways of limiting the voltage on the rectifier's smoothing capacitor:

Installation of a high-capacity smoothing capacitor C whose energy absorption capacity is equal to VS C * (ΔU 2) = VS L * 12. That the magnetic energy stored in the smoothing inductors (with inductance L) is taken up either by a large voltage swing ΔU (which is undesirable and which must be avoided) or by the capacitor with a correspondingly large capacitance C. I denotes the current in the equation. However, the installation of such a capacitor is an over-dimensioning for normal operation. This entails high costs, a consumption of installation space and an increase in weight.

An active electronic surge limiter can be used which switches a resistor in parallel with the smoothing capacitor when the voltage becomes too high. As a result, a discharge current flows, which causes the voltage on the capacitor to drop again or be limited. However, this solution is also expensive because in addition to the resistance, a powerful electronic switch, a drive unit, a voltage sensor and an electronic control circuit (with comparator) are needed.

The smoothing choke in the connection of the two DC voltage lines has the disadvantage that it too (with a tuning of the resonance frequency to eg below 100 Hz) is relatively large and heavy. In addition, such a throttle leads to electrical losses. Also it is with a smoothing choke with high inductance (typically in the range of 200 Hz / H) or higher is required to provide for each power converter its own absorption circuit, which is the second harmonic of the line frequency (ie eg 100 Hz for 50 Hz networks or 33 Hz for 16 2/3 Hz networks) filters. Two or more small suction circuits are however bulkier and therefore more difficult to accommodate than a single absorption circuit. In addition, eliminates the balancing effect by the staggered timing of both mains converters and the voltage ripple on the power converter smoothing capacitor therefore increases. The voltage ripple must in turn be compensated by increasing the capacitance of the smoothing capacitor.

According to the main aspect of this invention, an arrangement is proposed in which all motor power converters and power converters are to be galvanically connected. On the other hand, smoothing inductors of high inductance should be able to be provided between the motor power converter or the motor power converters on the one hand and the associated power converters on the other hand. The power converters should also be galvanically connected to each other, but spatially separated from each other.

It is an object of the present invention to provide a drive power supply for rail vehicles realized by more than one motor converter in which long distances are allowed: a) both between the motor converters b) and between the motor converters and the line converters c) and between the line converters to each other although the DC links are all galvanically connected. The disadvantages of a third smoothing reactor should be avoided.

In particular, the invention relates to an arrangement for the drive power supply of a rail vehicle, the arrangement comprising: a first DC link for connecting a first power converter with at least a first motor power converter, a second DC link for connecting a second power converter with the first motor converter or at least a second motor converter, a first smoothing capacitor through which the potentials and / or lines of first DC voltage intermediate circuit (capacitive, ie without galvanic connection) are connected to each other, a second smoothing capacitor, via which the potentials and / or lines of the second DC voltage intermediate circuit are interconnected.

Also, an embodiment of the invention relates to an arrangement for the drive power supply of a rail vehicle, the arrangement comprising: a first mains converter having a DC voltage terminal, with which it is connected to a first smoothing capacitor, wherein the DC voltage terminal has a plus and a minus pole, a second mains converter having a DC voltage terminal with which it is connected to a second smoothing capacitor, wherein the DC voltage terminal has a positive and a negative terminal, at least one motor power converter having a DC voltage terminal, with which it is assigned to a third, the respective motor power converter Smoothing capacitor is connected, wherein the DC voltage terminal has a plus and a minus pole, a connection line interconnecting the plus poles of the first power converter and at least one of the motor power converters (or the motor power converter), a connection line interconnecting the plus poles of the second power converter and at least one of the motor power converters (or the motor power converter), a connection line connecting the negative poles of the first mains converter and at least one of the motor power converters (or of the motor converter) and a connecting line connecting the minus poles of the second mains converter and at least one of the motor converter (or the motor converter).

In this case, at least one inductance (throttle) can be introduced in each case (for example in suitable interruptions) in the connecting lines.

The first DC intermediate circuit is assigned to the first mains converter. It can therefore also be referred to as the intermediate circuit of the first mains converter. The same applies to the DC link of the second mains converter. In particular, each of the DC voltage DC links each connect a mains converter with a motor power converter, which may be the same or different motor power converter.

The first smoothing capacitor is arranged in particular close to the first mains converter and can therefore be referred to as a smoothing capacitor of the first mains converter. The same applies to the second smoothing capacitor, which is arranged in particular close to the second mains converter. In this case, the respective smoothing capacitor is connected between the two potentials of the corresponding DC intermediate circuit, ie one electrode of the smoothing capacitor is connected to the higher potential and the other electrode is connected to the lower potential. The connection of a power converter to the smoothing capacitor associated with it is preferably always in such a way that the DC positive pole is directly connected to the one pole of the capacitor and the DC negative pole directly to the other pole of the capacitor is / is. Direct means that said inductors are not inserted between said poles in the connecting lines.

In a drive system with at least two line rectifiers, it is proposed to produce a galvanic electrical connection (also referred to below as a DC link connection) between a first DC smoothing capacitor (or DC link) and a second DC smoothing capacitor (or DC link).

In practice, the connection consists in particular of two parts (outgoing and return conductors), with the plus poles of the smoothing capacitors or intermediate circuits being connected to each other via a first connection and the respective negative poles of the smoothing capacitor intermediate circuits via a second connection.

In this way, a mesh (ie a circuit), which is formed by a respective smoothing capacitor of the two DC-link, by the first DC link, by the second DC link and, depending on the embodiment, optionally also of sections of the DC lines of the two intermediate , In other words, all lines belonging to the mesh lying on the path from the positive pole of the first smoothing capacitor to the positive pole of the second smoothing capacitor and all lines lying from the negative pole of the first smoothing capacitor to the negative pole of the second smoothing capacitor belong. It is assumed that valves of the first and the second mains converter are respectively switched in accordance with a clock frequency which lead to voltage pulses at the respective smoothing capacitor in the intermediate circuit. In the described manner galvanically interconnected intermediate circuits and thus interconnected power converters, the pulse frequencies in the two smoothing capacitors should be the same size, but be out of phase by 180 °, ie the voltage pulses occur by 180 ° out of phase in the two DC links. The phase offset causes the amplitudes of the voltage pulses are kept small due to the galvanic connection, if no smoothing reactor is present.

It is now further proposed to select or set the total inductance of the mesh so that the resonance frequency of the mesh, which is given in particular by the inductance of the mesh, and by the capacitances of the mesh (ie, the series connection of the smoothing capacitors), in one Range of +/- 10% is twice the pulse rate. Preferably, the inductance of the mesh is chosen so that the resonance frequency of the mesh (exactly as far as it is possible due to the tolerances in the electrical properties of the parts used, exactly) is equal to twice the pulse frequency.

In this case, the inductance L is given in particular by:

L = 1 / (8 V * fp ² * C),

where fp ^{2 is} the square of the pulse rate and where C is the capacitance of one of the two smoothing capacitors when the capacitances of the smoothing capacitors are equal (which is usually the case). If the capacities are not equal, C is the capacity of the substitute value C = 2 * (C1 * C2) / (C1 + C2), where C1 is the capacitance of one and C2 is the capacitance of the other smoothing capacitor.

The inductance value which satisfies the formula is referred to below as resonance inductance, which may be formed at least partially by at least one discrete component (hereinafter: the resonance choke). The total inductance of the mesh is therefore always composed of the inductances of the line connections of the mesh and optionally one (or more) possibly introduced additional (concentrated) inductance in the form of a coil or choke (the or the resonance chokes). So it is e.g. It is possible to select the cables as long and / or additionally to lay in loops with one or more turns, which increases the inductance of the cable connection, so that a resonance choke is not required or at least can be chosen smaller. In this case, the resonance choke does not have nearly the full resonance inductance, but the sum of the line inductances contributes significantly to the resonance inductance.

The term "smoothing capacitor" also includes the case where a plurality of the smoothing capacitors are connected in parallel and / or in series. "The capacity" of the smoothing capacitor then results from the total circuit of the capacitors. Optionally, further electrical components may be provided in the mesh, e.g. a fuse connected in series with the smoothing capacitor, or circuit breaker or electrical resistors.

The invention also relates to a corresponding method for operating the arrangement in one of its embodiments. In particular, in the method according to the invention the mains converters are operated so that the pulse frequencies mentioned arise with the phase offset. However, the pulse frequencies and their phase offset are also an objective Feature of the arrangement, bearing in mind that the control means for controlling the operation of the mains converter are set accordingly to switch the mains converter with the predetermined clock frequencies and phase angles.

The subject of the invention is also a method for producing the arrangement according to the invention in one of its embodiments, wherein in addition to the steps of providing all parts and connections of the arrangement, the step is also carried out that the inductance of the mesh is selected in the manner described.

The distributed power converter system presented here solves the problem of the spatial separation of the power converter without intermediate large smoothing choke with little additional effort. In particular, only a relatively small inductance in the form of a resonance choke or only a line connection whose inductance value in particular the o.g. Resonance condition is sufficient, needed. Thus, a locally distributed power converter system can be realized inexpensively. Also, a subsequent conversion of pure DC vehicles to AC vehicles or vehicles for optional DC or AC power supply is possible.

In practice, and referring to the above-mentioned numerical examples of the frequencies, the resonance frequency of the mesh in the embodiment is not below 100 Hz, but significantly higher. However, it is in the embodiment below 10 kHz.

Typically, the double pulse frequency is in the range of 0.7 to 3 kHz, so that the resonance inductance, and thus also the inductance of the resonance choke, can thereby be about 10 times smaller than a smoothing choke for a resonance frequency of less than 100 Hz. In particular, the power converters can each consist of a two-phase 4-quadrant or a vieφhasigen 4-quadrant. A four-quadrant vieφhasiger can be considered as two biphasic 4QS working on a common smoothing capacitor. During operation of the four-phase 4-quadrant controller, the two 4QS combined in one power converter preferably clocked 180 ° out of phase. This leads to a resulting pulse frequency of 4 times the clock frequency at the associated smoothing capacitor.

For the connection of the power converter to the power grid, one or more transformers may be provided, for. B. a single transformer with a primary winding on the network side and at least two secondary windings on the side of the power converter.

The case should also be included in which one or more motor power converters (reference numeral 16 in FIG. 1 to be described later) would not be connected to point P2 but to point P1. The illustrated case is only advantageous insofar as no additional direct DC current flows through the illustrated resonance choke (7) or connecting lines (7a, 28) with the same power distribution.

A plurality of motor power converters can be connected to at least one of the two DC voltage intermediate circuits or the smoothing capacitors of the mains converter. In this case, each of the motor power converters can be connected via at least one respective smoothing choke to the associated DC smoothing capacitor or intermediate circuit of the mains converter.

The power converters may be in a car or in a locomotive (eg locomotive or locomotive of a train) or z. B. in different be distributed together coupled cars or traction vehicles. Even then a clocking of the mains converter is possible, which leads to the phase offset of 180 ° of the resulting voltage pulses in the various smoothing capacitors. For example, a central control unit controls the clocking of the distributed grid converters by specifying the clock offset for each grid converter.

In particular, the invention also includes the case that the line length between the 4-quadrant plates is chosen exactly so that no additional, designed as (concentrated) device inductance (resonance choke) is more necessary. For example, If required, a line can be routed as a DC link connection with a correspondingly selected length in the vehicle as a loop.

The dimensioning of the inductance of the mesh is based on the following essential insight: It is not necessary to use a smoothing reactor which completely suppresses the current flow that can occur because of the phase-shifted voltage pulses. This principle would be applied if the resonant frequency were set below 100 Hz. Rather, a resonant AC is allowed by the DC link connection between the smoothing capacitors, the currents in the order of magnitude of the current on the AC side of the power converter leads. Nevertheless, there is a significant reduction in the current flowing into the smoothing capacitors. Experiments have shown that the RMS value of this current is reduced to approximately 1/4 compared to a large smoothing inductance arrangement, reducing the electrical losses to 1/16 as they increase quadratically with the RMS current. If the smoothing inductance is left out, effective currents for the smoothing capacitors, which are also far outside the permissible range, are obtained with only low line inductances in the range 1-5 μH. Since a resonance in the mesh is specifically sought, a corresponding inductance in the DC link connection between the smoothing capacitors may be referred to as resonance choke. An example of the currents with and without inductance will be described in the description of the figures.

Even if the double pulse rate at which the excitation of the resonant current occurs is not exactly equal to the resonant frequency, sufficient current in the DC link between the smoothing capacitors is still excited. Tuning the resonance frequency to a value of +/- 10% twice the pulse rate is therefore sufficient.

The fact that the resonance frequency of the mesh is set to relatively high frequencies, sufficient for both power converters, a single absorption circuit for damping the second harmonic oscillation of the mains frequency. For a mains with 162/3 Hz mains frequency, this harmonic is 33 Hz. For a 50 Hz mains it is 100 Hz. The reason for this is that the power flow at 33 Hz or 100 Hz is due to the much higher resonance frequency the mesh is practically not obstructed.

A significant advantage of the invention is the possibility of free placement of the power converter in the rail vehicle or train. This also applies to the retrofitting of vehicles that were originally designed for the supply from DC power grids.

The above-mentioned second aspect can be combined with the main aspect: As mentioned above, can arise during braking overvoltages on smoothing capacitor of the mains converter, z. B. when the electrical connection of the power converter to the contact wire of the power supply network is interrupted briefly. These overvoltages can be reduced by a snubber resistor, which is connected in parallel with the smoothing choke, via which the motor inverter is connected to the power converter is connected, is switched. When the voltage on the power converter smoothing capacitor rises, a discharge current flows back through this resistor in the direction of the motor converter so that the voltage rise on the smoothing capacitor of the mains converter remains within the permissible range. Typically, 300V to 600V overvoltage is still allowed. In each case, a circuit resistance is preferably provided for each of the smoothing reactors between the motor converter and the mains converter.

In the case of two-system vehicles (i.e., vehicles capable of operating both AC and DC networks), e.g. B. DC operation, a defined, predetermined smoothing inductance of the smoothing reactor between the motor converter and power converter need, the Beschaltungswiderstand can be made separable by a switch, so that the Beschaltungswiderstand is active only in AC operation, d. H. only in AC operation can flow current over it.

In DC operation, the 4QS mains converters with disconnecting contactors can also be disconnected so that no overvoltages can occur on the power converter smoothing capacitors.

Embodiments of the invention will now be described with reference to the accompanying drawings. The individual figures of the drawing show:

1 is a circuit diagram of an arrangement for driving power supply with two line rectifiers and two motor power converters,

Fig. 2 shows an embodiment of one of the shown in Fig. 1

Power converters,

Fig. 3 shows an embodiment of an alternative embodiment of a

Power converter, Fig. 4 is a diagram showing the time course of currents and

Stresses during operation of the arrangement according to FIG. 1,

5 is a diagram which describes the time profile of the voltage in one of the intermediate circuits according to FIG. 1,

Fig. 6 is a graph describing the time course of the voltage in one of the smoothing capacitors, when the inductance of the DC link connection between the power converter smoothing capacitors is not chosen according to the present invention, but is chosen so that a much lower resonant frequency is achieved , and

7 is a diagram showing the time course of currents and

Describes voltages, if the inductance of the mesh is only 4 μ \ Λ and no additional resonance choke is provided.

Fig. 1 shows an arrangement for supplying two traction motor groups 23, 24 of a rail vehicle with electrical energy from an AC supply network. The traction motors or traction motor groups 23, 24 are each connected via a three-phase connection with a motor power converter 15, 16. The assembly includes a current collector 27 connected to the primary winding of a transformer 26. The transformer 26 has two secondary windings, to each of which a power converter 1, 2 is connected.

A first motor power converter 15 is connected to the first power converter smoothing capacitor 3 via a galvanic connection consisting of two lines 21a and 21b (first DC voltage intermediate circuit). The DC intermediate circuit 21 thus has a first line connection 21a at a first electrical potential and a second line connection 21b at a second electrical potential. A second motor converter 16 is connected via a second line pair 22a and 22b (second DC link 22) to the second power converter smoothing capacitor 4. The DC voltage intermediate circuit 22 thus has a first line connection 22a at a first electrical potential and a second line connection 22b at a second electrical potential. Via a connection 28, a first potential (eg negative pole) of the first DC-smoothing capacitor 3 and a first same-name potential (eg also minus pole) of the second DC-smoothing capacitor 4 are connected to each other. Just as well, the connection can be made at any terminal point in the course of the line connection 21 a and 22 a.

In each case a smoothing throttle 9, 10 is arranged in the line connections 21b, 22b. However, these throttles could alternatively be arranged in the respective other line connection 21a and 22a. Likewise, one throttle could be located in connection 21b and the other throttle in connection 22a, or one throttle would be located in connection 21a and the other in connection 22b. In this respect, the illustration in Fig. 1 is only a special embodiment of the present invention.

Furthermore, a smoothing capacitor 3, 4 or 17, 18 are each arranged on the mains converter 1, 2 and on the motor converter 15, 16.

The second potentials of the mains converter (eg positive poles) are connected to one another via a connection 7a. In this case, the intermediate circuit connection 7a has an inductance 7 which can be achieved at least partially by one or more discrete components, for example the coil (or resonance choke) 7 shown in FIG. The connection 7a can also be connected to any terminal point P1 or P2 on the connecting line 21b or 22b. It is irrelevant for the invention, whether between the connection point P1 or P2 and the pole of Line rectifier smoothing capacitor is still disconnectors 5, 6 or other electrical components or not. Likewise, the connection 28 can be connected to any terminal point P3 or P4 of the connecting line 21a or 22a. Also, the illustrated inductance can be arranged in the line connection 28 or also in the following place: in the connection line between the positive pole of the first power converter smoothing capacitor and the point P1, in the connecting line between the negative pole of the first power converter smoothing capacitor and the point P3, in the connection line between the positive pole of the second power converter smoothing capacitor and the point P2, in the connecting line between the negative pole of the second power converter smoothing capacitor and the point P4. It is also possible to divide the illustrated inductance into smaller units and to distribute them to several or all of the above installation locations. Because all installation locations are part of the resonance mesh and the sum of the inductances is decisive for the resonance condition.

The mains converters 1, 2 are clocked in phase opposition, so that the voltage pulses of the voltages applied to the smoothing capacitors, which are thus impressed on the smoothing capacitors 3 and 4, are 180 ° out of phase with each other. The inductance is chosen so that the resonance frequency of the loop formed from the inductor 7, the power converter smoothing capacitors 3, 4 and the line connections 7a, 28 is equal to twice the pulse frequency of the voltage pulses of a power converter smoothing capacitor.

Furthermore, only a single absorption circuit 8 is connected with a series-connected of an inductance and a capacitance between the potentials of the connecting lines 21a and 21b. The absorption circuit could just as well be connected between the connection lines 22a and 22b. It would also be possible to switch the absorption circuit between the potentials 21b and 22a as well as between the potentials 21a and 22b. In this respect, the illustration in Fig. 1 is only a special embodiment of the present invention. Due to the DC link connection 7a, no second absorption circuit for damping the second harmonic frequency of the supply network is required. However, the present invention is not limited to arrangements with only one absorption circuit, it also applies in the case of several absorption circuits. The possibility with only one absorption circuit is only the simplest and therefore the most advantageous.

In the specific embodiment shown in FIG. 1, a respective switch 5, 6 is provided in the second connecting lines 21b, 22b. When the switches 5, 6 are opened, the right-hand part of the intermediate circuits 21, 22 with the motor converter 15, 16 connected thereto can be operated on a DC power supply network. In this case, also switches 13, 14 are opened, which are arranged in a parallel to the smoothing inductor 9, 10 extending current path in series with each of a resistor 11, 12. Thereby, the resistors 11, 12 are deactivated for operation on the DC power supply network, d. H. no current can flow parallel to the smoothing choke n 9, 10 in the line connections 21b, 22b. The presence of the resistors 11 and 12 and the switches 13 and 14 is not necessary for an application of the present invention, it represents only a particular embodiment.

2 shows the possible structure of one of the mains converters 1, 2 or both mains converters 1, 2 from FIG. 1. The symbols of the mains converter 1, the transformer 26 with one of the two secondary windings and the smoothing capacitor 3 are shown on the left in FIG , An equal sign symbolizes that the part to the left of the equal sign can be equal to the arrangement shown to the right of the equals sign. It can be seen that the power converter 1, 2 between the Connection points 35a, 35b for the second 21b and the first 21a line connection has two current paths, each formed by a series connection of two valves 31a, 31b and 32a, 32b. The series connection of two such valves is also called the "converter phase." For connection to the secondary winding of the transformer 26, connection points between the valves 31a, 31b and 32a, 32b are connected in each of the current paths to the opposite ends of the secondary winding. 31b, 32a, 32b, a freewheeling diode 33a, 33b, 34a, 34b is connected in antiparallel, thus being a two-phase four-quadrant controller In such an arrangement, the connection 35a is always the positive pole and 35b always the negative pole of the mains converter.

FIG. 3 shows that, unlike in FIGS. 1 and 2, the mains converters can also be four-phase four-quadrant actuators 1a. A four-phase four-quadrant is two-phase, four-quadrant, connected to the same smoothing capacitor, but four-phase on the AC side. Therefore, the connections on the AC side z. B. in pairs to different secondary windings of the transformer 26 are connected. Thus, the four-phase four-quadrant actuator four current paths with two valves in series 39a, 39b, 40a, 40b, 41a, 41b, 42a, 42b. The respective antiparallel-connected diodes are designated 43a, 43b, 44a, 44b, 45a, 45b, 46a, 46b.

In Fig. 4, the currents I_sek1, I_sek2 are represented by the secondary windings of the transformer 26 over a period of the mains voltage for the arrangement of FIG. 1 in the specific embodiment of the power converter of FIG. It can also be seen on the AC side of the power converter, the current ripple caused by the switching of the power converter valves (caused by the voltage pulses generated during clocking), which are out of phase. Furthermore, the charging current I_Czk1 of the smoothing capacitor 3 and the current I dross through the inductance 7 are the DC link connection 7a shown. It can be seen that the last two currents are only in the range of plus / minus 2000 A. In addition, it can be seen that the current I_dross through the inductance 7 and the current I_Czk1 of the smoothing capacitor 3 likewise oscillate in opposite phase, wherein partially during a half-oscillation an amplitude maximum of one current is offset by two amplitude maxima and a local minimum of the other current. Thus, there is some quenching effect that reduces the overall rms value of the capacitor current.

Experiments with a much smaller inductance 7, e.g. without a concentrated resonance choke and too short a cable length, however, gave currents through the cable connection and charging currents of the capacitor 3, which were larger by more than a factor of two (FIG. 7). This leads to impermissibly high overall rms values of the charging current, e.g. B. significantly more than 1700 A and would destroy the capacitors quickly.

Also, the ripple of the voltages in the smoothing capacitors 3 and 4 was significantly smaller in the case of the inventive dimensioning (eg 24 μH) of the inductance in the DC link (see Fig. 5) compared to the classical dimensioning (e.g. 400 // H) of the inductance as smoothing choke (see FIG. 6).

Claims

claims

An arrangement for the drive power supply of a rail vehicle or rail vehicle association, the arrangement comprising: a first power converter (1) having a DC voltage terminal, with which it is connected to a first smoothing capacitor (3), wherein the DC voltage terminal a plus and a negative terminal, which are connected to a plus and minus pole of the smoothing capacitor (3), a second mains converter (2) having a DC voltage terminal, with which it is connected to a second smoothing capacitor (4), wherein the DC voltage terminal is a plus and a negative terminal, which are connected to a plus and minus pole of the smoothing capacitor (3) at least one motor power converter (15, 16) having a DC voltage terminal, with which it to a third, the respective motor power converter (15, 16) associated smoothing capacitor (17, 18) is connected, wherein the DC connection has a positive and a negative terminal, an electrical connection (21 b), which connects the positive poles of the first mains converter (1) and at least one (15) of the motor power converter with each other, an electrical connection (22 b), the plus Pole of the second mains converter (2) and at least one (16) connects the motor converter, an electrical connection (21a) interconnecting the negative poles of the first mains converter (1) and at least one (15) of the motor power converters, an electrical connection (22a) connecting the negative poles of the second mains converter (2) and at least one (16) the motor power converter connects to each other, a first galvanic connection (7a) via which the positive pole of the first smoothing capacitor (3) is galvanically connected to the positive pole of the second smoothing capacitor (4), a galvanic connection (28) via which the negative pole of the first smoothing capacitor (3) is galvanically connected to the negative pole of the second smoothing capacitor (4), so that at least the first smoothing capacitor (3), the second smoothing capacitor (4), the first galvanic connection (7a) and the second galvanic connection (28) form a loop (circuit), wherein valves (31, 32) of the first and the second mains converter (1, 2) each corresponding to a clock frequency which result in voltage pulses having a pulse frequency at the first or second smoothing capacitor (3, 4), characterized in that the total inductance of the mesh is chosen so that the resonance frequency of the mesh is in a range of plus / minus 10%. is twice the pulse rate.

2. Arrangement according to the preceding claim, wherein the total inductance of the mesh is chosen so that the resonance frequency of the mesh, which is determined at least by the inductance of the mesh and the capacity of the mesh is equal to twice the pulse rate.

3. Arrangement according to one of the preceding claims, wherein the pulse frequencies at the first and the second smoothing capacitor (3, 4) are the same size, but are 180 ° out of phase.

4. Rail vehicle with an arrangement according to one of claims 1 to 3.

5. A method for producing an arrangement for the drive power supply of a rail vehicle, comprising the following steps:

Connecting each of the positive poles and the negative poles of a first mains converter (1), a first smoothing capacitor (3) assigned to the first mains converter (1) and a motor converter (15),

Connecting each of the plus poles and the negative poles of a second mains converter (2), the second power converter (2) associated second smoothing capacitor (4) and the motor converter or at least one other Motorstromrichters (16), galvanically connecting the positive pole of the first smoothing capacitor (3) the positive pole of the second smoothing capacitor (4) by a first galvanic connection (7a), galvanically connecting the negative pole of the first smoothing capacitor (3) to the negative pole of the second smoothing capacitor (4) by a second galvanic connection (28), so that at least the first smoothing capacitor (3), the second smoothing capacitor (4), the first galvanic connection (7a) and the second galvanic connection (28) forming a loop (circuit), characterized by Adjusting the total inductance of the mesh such that the resonant frequency of the mesh, given by at least the mesh inductance and the mesh capacities, is in a range of plus / minus 10% double the pulse rate of voltage pulses in the first and second meshes Smoothing capacitor (3, 4), which arise during operation of the arrangement due to switching operations of valves of the power converter (1, 2).